The present invention relates to a roller for thermally and stably fixing a toner image on copy paper. Conventional electrophotographic copying machines and laser printers incorporating electronic photographing systems are already well known to the public. These devices cause the toner image of either draft pictures or recorded information to be generated on a photoreceptor which is the basic medium for recording pictures and information before the toner image is transferred onto copy paper. The toner image remains unfixed immediately after being transferred onto copy paper and is eventually fixed after passing through a toner fixation device. There are a variety of toner fixing devices. A roller which theremally fixes the toner image is widely popular. Of several rollers forming the thermal fixing roller unit, the surface of the roller coming into contact with the toner image on the copy paper is controlled so that it constantly maintains the proper toner fixable temperature throughout the copying operation. The thermal fixing roller is heated by a heater either inside or outside the thermal fixing roller. The heater is properly controlled so that the surface of the roller constantly maintains the proper toner fixable temperature. For example, the heater may be installed in the center of the rotary shaft so that the roller is heated by heat radiating from the heater. Normally, to improve the roller's efficiency in absorbing heat from the heater, the internal surface of the roller is coated with black paint. Normally, the black-coated portion is provided only along the internal surface of the roller to match the toner fixing external surface of the roller. In addition, to ensure a greater heating effect, either an infrared lamp or a halogen lamp is commonly used with the heater. The halogen lamp is made of a glass tube comprised of tungsten filaments with halogen sealed inside. Both ends of the glass tube are sealed flat. The externally connected terminals inside the sealed portion of the glass tube are electrically connected to filaments via metal foil such as molybdenum foil to feed electricity to the filaments. Normally, when a halogen lamp is provided inside the toner fixing roller, the externally-connected terminal of the heater lamp is arranged so that the terminal itself projects from the toner fixing roller. Thus, the sealed portion of the heater lamp is positioned so that the sealed portion is opposite to the roller bearing. The inner surface of the bearing at the end of the roller unit has a bare metal surface such as aluminum, which reflects infrared rays from the heater lamp. Some of the reflected beams reach the sealed portion of the halogen lamp in the center of the rotary shaft of the toner fixing roller. As a result, the sealed portion is heated. Since the sealed portion of the heater lamp is extremely vulnerable to heat, the heat adversely affects the service of the halogen lamp itself. Metal foils are also used in the sealed portion of the halogen lamp. In particular, of all the lamp components, molybdenum foil most easily causes oxidation to occur. Thus it can be cut off easily. The oxidation is promoted by heating and significantly shortens the service life of the lamp. The metal foil is easily heated by the infrared rays reflected from the halogen lamp, thus accelerating the disconnecting time of the heated portion and significantly shortening the service life of the heater lamp as well.